Field of the Invention
This invention relates to swaging tools for use in swaging fittings, and more particularly to a swaging tool for swaging axially swaged fittings, to join tubes or pipes.
Related Art
In manufacturing aircraft, the assembly of different systems for the aircraft may require pipes, tubing, or other materials to be connected to each other. For example, in installing a hydraulic system in an aircraft, different tubes may be connected to each other to create a seal to contain fluids, such as hydraulic fluids, for the system.
One manner in which different pieces of tubing or other assemblies that may carry fluids can be connected to each other is by swaging. Swaging is a metal forming technique in which dimensions of an item are altered using a component into which the item is forced. In these examples, a metal tube may be connected to a swage fitting. The swage fitting may deform the metal tube to create a seal between the metal tube and the swage fitting. Another end of the swage fitting may be connected to another metal tube to connect the two tubes together. Similar types of processes may be performed for installing tubing for wiring or other items within an aircraft.
The swage fitting has an axis that may be aligned around or about the axis of the tubing. This type of swage fitting is also referred to as an axial swage fitting. The swage fitting may be moved towards the tubing to deform the tubing and/or swage fitting to create a connection. In these examples, the connections may be sealed connections, such that fluids do not leak out of the connection.
Prior art tools for assembling such a fitting to a fluid conduit often include a fixed jaw, a moveable jaw and one or more hydraulic cylinders for moving the moveable jaw toward the fixed jaw. The moveable jaw pushes a ring axially over the fitting body causing the swage fitting to compress or move radially into the fluid conduit to provide a seal and a mechanical connection. When the swaging is complete, hydraulic pressure in the one or more hydraulic cylinders is released allowing a return spring or some other method to return the moveable jaw to the starting position. This allows the tool to be removed from the fitting assembly. Examples of prior art installation tools are taught in U.S. Pat. No. 4,189,817 (“Hydraulic Assembly Tool for Tube Fittings”); U.S. Pat. No. 5,305,510 (“Hydraulic Assembly Tool with Improved Load Bearing Arrangement for Tube Fittings”); U.S. Pat. No. 5,694,670 (“Secure Swaging Tool”); U.S. Pat. No. 6,434,808 (“Compact Installation Tool”); and U.S. Pat. No. 6,618,919 (“Remote Actuation of Installation Tooling Pump”); U.S. Pat. No. 7,984,538 (“Hydraulic Hand Tool”); and U.S. Pat. No. 8,256,079 (“Apparatus of Swaging Components”), all of which are expressly incorporated herein by reference.
The tools for swaging axial swage fittings to tubes typically use a hydraulic pump that connects to the tool by a hose. Other drive mechanisms such as screw drives are also suitable for this device. These tools and/or the hoses for the pumps along with the tools to perform swaging are moved into the interior of the aircraft to perform swaging for systems being installed. The operator must support the full weight of the tool and keep the tool in alignment with one hand while pressurizing the pump with the other hand. Alternatively, the fitting installation is performed on a bench. An axially swaged fitting may require 10,000 pounds per square inch of hydraulic pressure to install the fitting.
Most axial swage tools have U-shaped fixed and moveable jaws that allow easy insertion and removal of the swage fitting. However, the U-shape also allows the fitting to easily move out of position as the hydraulic pressure is applied causing a misalignment. This can result in the tool breaking, and a dangerous situation for the operator because of the very high forces being generated.
Some axial swage tools have a cover that are attached by other means that completely encircle the opening and fastening on one or both sides. Such devices are disclosed in U.S. Pat. No. 7,984,538 and U.S. Pat. No. 8,256,079. This can be inconvenient and cumbersome, in that the cover must be fastened and unfastened with each attachment. U.S. Pat. No. 5,305,510 discloses spring-loaded retainers on the sides of the moveable jaw to secure the fitting. The retainers are small, complicated and easily damaged. Further, when high pressures are applied the springs could inadvertently release and fail to secure the fitting.
Therefore, it would be advantageous to have a method and apparatus that overcomes the disadvantages described above.
None of the above prior art devices do what the present invention does.